Weight loss at six months is the surrogate of long-term treatment outcomes for obese Chinese with a BMI less than 35 kg/m2 undergoing Roux-en-Y gastric bypass

Roux-en-Y gastric bypass (RYGB) is considered the gold standard procedure for bariatric surgery that leads to sustained weight loss and amelioration of obesity-related comorbidities. To verify long-term efficacy and safety and to investigate the influence of early weight loss on post-RYGB long-term weight maintenance in obese Chinese with body mass index (BMI) < 35 kg/m2. All patients were followed up for evaluating the variations in their BMI, percentage of excess weight loss (%EWL), and total body percentage weight loss (%TWL). Linear regression models were applied to evaluate the effects of early weight loss on successful weight maintenance. Optimal cutoff values were analyzed via plotting the receiver operative characteristic (ROC) curve. In the current study, 143 patients were recruited. Preoperative BMI and weight were recorded as 32.24 (29.39–33.12) kg/m2, and 88.90 ± 9.52 kg, respectively. At 1, 3, and 5 years, successful weight loss i.e., greater than 25% TWL was attained by 46.85%, 37.76%, and 37.06% of patients, respectively. The obtained data revealed that %TWL at 0.5 years was considerably associated with %TWL for up to 5 years (P-value <0.001). Based on the ROC curve, %TWL of 24.39% at 0.5 years best predicted effective weight loss at 5 years (sensitivity 71.70%, specificity 82.22%). RYGB is a safe and effective approach for weight loss and %TWL at 6 months might be used for predicting weight maintenance up to 5 years post-RYGB in obese Chinese with a BMI <35 kg/m2.